When flies having a gray body and normal wings were crossed with flies having a black body and vestigial wings, the F2 generation showed a phenotypic ratio of 3:1, and not 9:3:3:1.

Which of the following could be a correct explanation for this ratio?

A- Genes for body and wing size were on the same chromosome and inherited together
B- Genes for body and wing size assort independently
C- Genes for body color and wing size are inherited separately from each parent